For several years, autumn and winter winds have carried a ghost fleet of derelict boats to the coast of northern Japan. Many of the boats were empty, although some carried corpses. This year has set a new record — 89 derelict vessels so far this year, as compared to 59 in 2017.   In the previous five years, an average of 44 boats drifted ashore each year. This year 12 corpses have been found on five of the derelicts. In 2015, 25 bodies were found on the drifting boats.

The boats appear to originate from the Korean peninsula, carried across the Sea of Japan on seasonal winds.  Some of the boats are thought to have contained refugees seeking to escape from oppression in North Korea. In 2017, eleven North Korean survivors were found on drifting boats, along with fifteen dead. 

It is also considered likely that some of the vessels are fishing boats. North Korean fishermen are under intense state pressure to fulfill fishing quotas for the Kim Jong Un regime and are reported to soften sail without adequate fuel or supplies.